This invention relates to a method of and structure of manufacturing open top, walled members such as troughs, runners, ladles and other vessels which are used for containing and processing molten iron and steel. It is well known in the art that such open, top walled members may have sufficient structural integrity to support alone molten metal poured therein.
Conventionally, troughs and runners for transporting molten iron and steel are constructed in situ near a tap spout of a blast furnace or other molten metal container. The mold for the trough or runner utilizes the existing walls of a trench or other existing structure as the outer (lower) walls of the mold. The inner (upper) walls of such molds have conventionally been formed of heavy steel plates spaced from the outer walls leaving only an open space between the outer and inner mold walls in which to pour the casting compound and to provide a venting area for the release of moisture during setting of the casting compound. In the past, heavy oil or grease was placed on the sides of the inner walls facing the outer walls to allow for more ease in the removal of the inner wall from the casting compound.
Inner walls of molds have also been made of a consumable, open mesh, galvanized steel screen. Typically, there are adequate openings in the mesh screen to permit venting of moisture from the drying compound. The mesh screen is not removed and is melted by the molten metal being introduced into the finished trough or runner.
In some instance it is desired to use the mesh screen a multiple number of times for the formation of other troughs or runners. This provides a savings in cost by preserving the screen material. Manufacturing time is reduced by forming a multiple number of identical troughs or runners from a single mesh screen instead of creating a mesh screen for each trough or runner. This also provides a consistency in the quality of each trough or runner.
In the past, when reusing the mesh screen for forming additional containment members, the casting compound would often stick to the screen. Chunks of the casting compound would be removed along with the screen when the screen was lifted from the mold. Also, the casting compound would ooze through holes in the screen and stick to framework provided to support the screen. This required a greater amount of time and effort to remove the screen.
Accordingly it would be desirable to have a form which overcomes the disadvantages described above, is reusable and can be efficiently and quickly removed from the mold.